You are tasked with the IP address assignment of the frame relay network.
With regards to network layer address assignment, which of the following are
true
regarding the effects of using frame relay sub interfaces on a physical
interface?
A. The network layer address of each sub interface must be in the same
subnet as the physical interface address.
B. The network layer address of each sub interface must be approved by IANA
C. The network layer address must be removed from the physical interface.
D. The network layer address of each sub interface must be the same as the
physical interface address.
E. The sub interfaces should be assigned the network broadcast address of
the
physical interface.
F. None of the above.

the addresses to be assigned in the subinterface do not need to be approved
by IANA since in a internal network you can have the control wheather they
ar private or public (in case your network does not have access to the
internet).
about C, yes is really needed the otherwise you will have 2 different
interfaces conneceted to the same network and/or the main serial trying to
reach certain network that maybe reachable some other way.